Hujing Island lies roughly 8 nautical miles south of Magong Harbor and is one of Penghu’s four major outer islands. Despite covering less than 1 square kilometre, it is well known for the Hujing Sunken City — a sea cave surrounded by legends of a submerged ancient settlement — and for the WWII-era Japanese military installations scattered across its terrain. Owing to its strategic location, structures such as the “South Advance Command Post” and a number of artillery and outpost ruins from both the Japanese colonial period and the post-war ROC era still stand on the island, drawing the curiosity of visitors alongside the sea cave. (Note: the active Penghu Prison operated by the Ministry of Justice is in Dingwan Village, Hushi Township on Penghu’s main island — not on Hujing.) Reaching the island requires a ferry from Magong Harbor (approximately 20 minutes); there is no regular bus connection, so advance planning is essential.
Highlights
The Hujing Cave is the island’s defining natural feature. At low tide, a deep sea cave is exposed along the northern shoreline — roughly 5 metres (16 feet) high at its entrance and large enough to shelter dozens of people. Local tradition describes the cave as the remnant of a sunken ancient city, but geologically it is basalt shaped over centuries by wave erosion and of geological interest. Water pools inside and tidal fluctuations are considerable; at low tide visitors may briefly enter and photograph the interior, though venturing far inside is not advisable.
The other main point of interest is the cluster of WWII-era Japanese military structures on the island. The most prominent is the elevated “South Advance Command Post,” reportedly used as a forward staging post during Pacific War operations. Building foundations, underground tunnels, defensive earthworks, and abandoned outposts overgrown with banyan trees can also be found nearby. Some structures have partially collapsed, but the overall layout retains educational value. On the island’s western side, Japanese-era artillery emplacement ruins and former post-war ROC military outpost sites add further historical layers.
Getting There and Nearby
There is no bus service to Hujing Island. As an outer island, it can only be reached by ferry from Magong Harbor. Private ferry operators typically run morning departures with afternoon returns; the crossing takes about 20 minutes. The most convenient approach is to book a day-trip package through a Penghu travel agency, or contact ferry companies at Magong Harbor directly (such as Penghu Express Ferry) to confirm that day’s sailings.
Time on the island is governed by the tides. The best window for seeing the cave is at low tide, which typically allows only 2–3 hours. Check the Penghu tide forecast and choose a sailing that coincides with low tide. During winter, frequent northeast monsoon winds can cause cancellations or delays.
Facilities on the island are limited — there are no convenience stores or restaurants, only a basic rest area. Bring your own drinking water, snacks, and sun protection. A stay of 3–4 hours is generally sufficient to walk around the island and visit the main sights.
If you plan to visit other Penghu outer islands on the same trip, Magong Harbor also has ferries to Tongpan Island and Qimei Island, which can be combined into a single itinerary. See Penghu Ferry Information for island-wide transport details.